The present invention relates to a method for forming a tube used in a heat exchanger including a plurality of indentations that increase heat transfer between a fluid flowing through the tube and a fluid flowing around the tube.
A shell and tube heat exchanger is used to cool fluids in various automotive applications, including exhaust gas recirculation coolers and power steering devices. In an engine gas recirculation system, an exhaust fluid flows inside the tube and exchanges heat with a coolant flowing around the tube. The exhaust fluid closer to the tube wall cools faster than the exhaust fluid flowing in the center of the tube.
In the prior art, the tubes in the heat exchanger can be bent or twisted to create turbulence in the exhaust fluid and to provide a non-linear flow path to increase heat transfer.
There are several drawbacks to the bent or twisted tubes of the prior art. For one, it is difficult to manufacture the tubes. Additionally, it is both costly and laborious to twist and bend the tubes to the desired shape.
Hence, there is a need in the art for a method for shaping a tube used in a heat exchanger that overcomes the drawbacks and shortcomings of the prior art.